Videotape
147952
223912187
2008-07-06T13:52:57Z
Lightbot
7178666
Units/dates/other
[[Image:Assorted video tapes.JPG|thumb|300px|An assortment of video tapes]]
'''Videotape''' is a means of recording images and sound onto [[magnetic tape]] as opposed to [[film stock|movie film]].
In most cases, a [[helical scan]] video head rotates against the moving tape to record the data in two dimensions, because video signals have a very high bandwidth, and static heads would require extremely high tape speeds. Video tape is used in both video tape recorders (''VTRs'' or, more common, video cassette recorders ([[VCR]]s)) and [[Camcorder|video camera]]s. Tape is a linear method of storing information, and since nearly all video recordings made nowadays are digital, it is expected to gradually lose importance as non-linear/random access methods of storing digital video data are becoming more common.
== Early formats ==
The electronics division of entertainer [[Bing Crosby]]'s production company, Bing Crosby Enterprises (BCE), gave the world's first demonstration of a videotape recording in Los Angeles on November 11, 1951. Developed by [[Jack Mullin|John T. Mullin]] and Wayne R. Johnson since 1950, the device gave what were described as "blurred and indistinct" images, using a modified [[Ampex]] 200 tape recorder and standard quarter-inch (0.6 cm) audio tape moving at 360 inches (9.1 m) per second.<ref>"Tape Recording Used by Filmless 'Camera'," ''New York Times'', Nov. 12, 1951, p. 21. Eric D. Daniel, C. Denis Mee, and Mark H. Clark (eds.), ''Magnetic Recording: The First 100 Years'', IEEE Press, 1998, p. 141. ISBN 0-070-41275-8</ref> A year later, an improved version, using one-inch (2.6 cm) magnetic tape, was shown to the press, who reportedly expressed amazement at the quality of the images, although they had a "persistent grainy quality that looked like a worn motion picture." Overall, the picture quality was still considered inferior to the best [[kinescope]] recordings on film.<ref>"Tape-Recorded TV Nears Perfection," ''New York Times'', Dec. 31, 1952, p. 10.</ref> Bing Crosby Enterprises hoped to have a commercial version available in 1954, but none came forth.<ref>"New Deal on TV Seen at Parley," ''New York Times'', May 1, 1953, p. 30.</ref> BCE demonstrated a color model in February 1955, using a longitudinal recording on half-inch (1.3 cm) tape, essentially similar to what [[RCA]] had demonstrated in 1953 (see below). [[CBS]], RCA's competitor, was about to order BCE machines when Ampex introduced the superior Quadruplex system (see below).<ref>Daniel et al., p. 148. BCE was acquired by [[3M]] Company in 1956.</ref>
[[RCA]] demonstrated the magnetic tape recording of both black-and-white and color programs at its [[Princeton, New Jersey|Princeton]] laboratories on December 1, 1953.<ref>"Magnetic Tape Used By RCA to Photograph Television Program," ''The Wall Street Journal'', Dec. 2, 1953, p. 1.</ref> The high-speed longitudinal tape system, called Simplex, in development since 1951, could record and play back only a few minutes of a program. The color system used half-inch (1.3 cm) tape to record five tracks—one each for red, blue, green, synchronization, and audio. The black-and-white system used quarter-inch (1.9 cm) tape with two tracks, one for picture and one for sound. Both systems ran at 360 inches (9.1 m) per second.<ref>Stewart Wolpin, [http://www.americanheritage.com/articles/magazine/it/1994/2/1994_2_52.shtml The Race to Video], ''Invention & Technology'', Fall 1994.</ref> RCA-owned [[NBC]] first used it on the ''The Jonathan Winters Show'' on October 23, 1956, when a pre-recorded song sequence by [[Dorothy Collins]] in color was included in the otherwise live program.<ref>Ed Reitan, [http://novia.net/~ereitan/rca-nbc_firsts.html RCA-NBC Firsts in Color Television (commented)].</ref>
The [[BBC]] experimented from 1952 to 1958 with a high-speed linear videotape system called [[VERA videotape format|VERA]], but this was ultimately unfeasible. It utilized 1/2 inch (1.27 cm) tape traveling at 200 inches (5.08 m) per second.
== Broadcast video ==
=== Quad ===
[[Image:2-inch Quad Tape Reel with miniDV cassette.jpg|thumbnail|250px|A reel of 2 inch quad videotape compared with a modern-day [[miniDV]] videocassette]]
The first practical professional videotape machines were the [[2" Quadruplex videotape|Quadruplex]] machines introduced by [[Ampex]] in the [[United States]] on April 14, 1956. Quad employed a transverse (scanning the tape across its width) four-head system on a two-inch (5.08 cm) tape, and linear heads for the soundtrack. CBS first used the Ampex Mark IV at its Television City studios in Hollywood on November 30, 1956 to play a delayed broadcast of ''Douglas Edwards and the News'' from New York to the Pacific Time Zone.<ref>Ampex Corporation, [http://www.ampex.com/03corp/03corp.html Ampex Chronology].</ref>
Although Quad became the industry standard for 20 years, it had drawbacks such as an inability to freeze pictures, no picture search, and in early machines, a tape could only reliably be played back using the same set of hand-made tape heads, which wore out very quickly. Despite these problems, Quad could produce excellent images.
Unfortunately, very few early videotapes still exist. The high cost of early videotapes meant that most broadcasters erased and reused them, and (in the United States) regarded videotape as simply a better and more cost-effective means of time-delaying broadcasts than the previous [[kinescope]] technology, which recorded television pictures onto photographic film. It was the four time zones of the continental United States which had made the system very desirable in the first place. However, some early broadcast videotapes have survived, including ''[[The Edsel Show]]'', broadcast live in 1957, and 1958's ''[[An Evening With Fred Astaire]]'', the oldest color videotape of an entertainment program known to exist (the oldest color videotape is the May 1958 dedication of the [[WRC-TV]] studios in [[Washington, DC]]). In 1976, [[NBC]]'s 50th anniversary special included an excerpt from a 1957 color special starring [[Donald O'Connor]]; despite some obvious technical problems, the color tape was remarkably good. Subsequent videotape systems have used helical scan, where the video heads record diagonal tracks (of complete fields) on to the tape.
=== Type C & Type B ===
The next format to gain widespread usage was the [[1 inch type C videotape|1" (2.54 cm) Type C]] format from 1976 onward. It introduced features such as shuttling and still framing, but the sound and picture reproduction attainable on the format were of just slightly lower quality than Quad (although 1" Type C's quality was still quite high). However, unlike Quad, 1" Type C machines required much less maintenance, took up less space, and consumed much less electrical power.
In Europe a similar tape format was developed, called [[1 inch type B videotape|Type B]]. Type B machines (also known as BCN) used the same 1" tape as Type C but they lacked C's shuttle and slow-motion options. The picture quality was slightly better, though. Type B was the broadcast norm in continental Europe for most of the 1980s.
=== Cassette formats ===
[[Image:U-matic.jpg|thumb|250px|A U-matic tape]]
In 1969, [[Sony]] introduced a prototype for the first widespread video cassette, the 3/4" (1.905 cm) [[composite video|composite]] [[U-matic]] system, which Sony introduced commercially in September 1971 after working out industry standards with other manufacturers. Sony later refined it to ''Broadcast Video U-matic'' or BVU.
Sony continued its hold on the professional market with its ever-expanding 1/2" (1.27 cm) [[component video]] [[Betacam]] family (introduced in 1982), which, in its digital variants, is still among the professional market leaders.
[[Panasonic]] had some limited success with its [[Panasonic MII|MII]] system, but never could compare to Betacam in terms of market share.
The next step was the [[digital]] revolution. Among the first digital video formats Sony's [[D1 (Sony)|D-1]], which featured uncompressed digital component recording. Because D-1 was extremely expensive, the composite [[D2 (video format)|D-2]] and [[D3 video|D-3]] (by Sony and Panasonic, respectively) were introduced soon after. Ampex introduced the first compressed component recording with its [[DCT (videocassette format)|DCT]] series in 1992. Panasonic trumped D-1 with its [[D5|D-5]] format, which was uncompressed as well, but much more affordable.
[[DV]] standard debuted in 1996 and has become widely used both in its native form and in more robust forms such as Sony's [[DVCAM]] and Panasonic's [[DVCPRO]] as an acquisition and editing format. However, due to concerns by the entertainment industry about the format's lack of [[copy protection]], only the smaller MiniDV cassettes used with camcorders became commonplace, with the full-sized DV cassettes restricted entirely to professional applications.
For camcorders, Sony adapted the Betacam system with its [[Digital Betacam]] format, later following it up with the more low-cost [[Betacam SX]] and [[MPEG IMX]] formats, and the semiprofessional [[DV]]-based [[DVCAM]] system. Panasonic used its [[DV]] variant [[DVCPRO]] for all professional cameras, with the higher end format [[DVCPRO50]] being a direct descendant. [[JVC]] developed the competing [[Digital-S|D9/Digital-S]] format, which compresses video data in a way similar to DVCPRO but uses a cassette similar to [[S-VHS]] media.
=== High definition ===
The introduction of [[High-definition television|HDTV]] production necessitated a medium for storing high-resolution video information. In 1997, Sony bumped its Betacam series up to HD with the [[HDCAM]] standard and its higher-end cousin [[HDCAM SR]]. Panasonic's competing format for cameras was based on DVCPRO and called [[DVCPRO HD]]. For VTR and archive use, Panasonic expanded the D-5 specification to store compressed HD streams and called it [[D5 HD|D-5 HD]].
== Home video ==
=== VCRs ===
[[Image:Vhs cassette bottom.jpg|thumb|250px|Bottom view of [[VHS]] videotape cassette with magnetic tape exposed]]
The first domestic [[videocassette recorder]]s were launched in 1971 (based around [[U-matic]] technology), but it was not until Sony's [[Betamax]] (1975) and JVC's [[VHS]] (1976) were launched that videotape moved into the mass market, resulting in what came to be known as the "[[videotape format war]]", which VHS finally won. VHS is still the leading consumer [[VCR]] format, since its follow-ups [[S-VHS]], [[W-VHS]] and [[D-VHS]] never caught up in popularity. It has, however, been displaced in the prerecorded video market by the nonlinear and disc based [[DVD]], although like [[vinyl records]] may not become completely obsolete owing to the large number of videocassettes owned by consumers.
The size of a standard VHS tape cassette is 1" x 4" x 7 1/2". Following in the footsteps of standard VHS came other consumer videotape formats such as 8mm video, Hi8, and digital 8, VHS-C (compact) and S-VHS-C.
With the recent popularity of the DVD format, many people have started considering their videotapes obsolete and are happy to sell them off for considerably cheap prices at venues such as flea market or [[car boot sale]]s etc.
=== Camcorders ===
[[Image:DV tape sizes 2.jpg|thumb|250px|DV cassettes<br>Left to right: DVCAM-L, DVCPRO-M, MiniDV]]
Early consumer [[camcorders]] used full-size VHS or Betamax tapes. Later models switched to more compact formats like [[8 mm video format]] (later replaced by [[Hi8]] and [[Digital8]]) and [[VHS-C]] (later replaced by Super VHS-C) tape.
Presently, [[MiniDV]] is the most popular format for tape-based consumer camcorders, providing near-broadcast quality video and sophisticated nonlinear editing capability on consumer equipment; however, though intended as a digital successor to VHS, MiniDV VCRs are not widely available outside professional circles.
Sony introduced a new camcorder cassette format with [[MicroMV]], but consumer interest was low due to the proprietary nature of the format and limited support for anything but low-end Windows video editors, and Sony shipped the last MicroMV unit in 2005.
For high definition, the most promising system seems to be [[HDV]], which uses MiniDV media to store a roughly broadcast-quality [[High-definition television|HDTV]] data stream.
The latest trend in consumer camcorders is to switch from tape-based to tapeless solutions, like built-in HDDs, optical disks and solid-state media.
== References ==
{{reflist}}
==See also==
* [[VHS]]
* [[VTR]]
==External links==
* [http://palimpsest.stanford.edu/byorg/abbey/an/an21/an21-7/an21-708.html The Loss of Early Video Recordings]
* [http://web.archive.org/web/20040603152849/http://www.tvhandbook.com/History/History_recording.htm ''History of Recording Technology''] (WayBack Machine)
* [http://web.archive.org/web/20040603153341/www.tvhandbook.com/History/History_tape.htm ''History of Magnetic Tape''] (WayBack Machine)
{{Commons|Videotape}}
{{Homevid}}
[[Category:Video storage]]
[[cs:Videokazeta]]
[[de:Videokassette]]
[[es:Videocinta]]
[[fr:Cassette vidéo]]
[[ko:비디오테이프]]
[[it:Videocassetta]]
[[hu:Videokazetta]]
[[nl:Videoband]]
[[ja:磁気テープ]]
[[pl:Kaseta wideo]]
[[pt:Videoteipe]]
[[ru:Видеокассета]]
[[sv:Videoband]]
[[zh:录影带]]